In the list of Visited Websites, look for traintool.com. Click on the line containing traintool.com (the text before traintool.com should be the subdomain you are using, here it's test.traintool.com, usually it is thenameofyourcompany.traintool.com)

The privacy settings options will now become colored instead of grey, and you can select your privacy setting for this domain. Click 'Always allow'.

When you click 'Always allow', the icon in the Visited Websites list will change to a green checkmark.